Field
The disclosure relates to a light source apparatus which can be used in various applications such as a lighting equipment.
Description of the Related Art
Recently, a light source apparatus using a laser diode (LD) or a light emitting diode (LED) is proposed and put into practical use as a lighting equipment which can be applied to various applications such as a lighting equipment, a display, a projector and a backlight in the view point of reduction of power consumption, downsizing and design. Specifically, the laser diode can condense a light into a small area easily, and for example, a light source apparatus which can emit lights in various wavelengths with a high luminance can be realized by placing a phosphor at the light condensed position.
In this case, it is preferable to condense a plurality of lights emitted from a plurality of laser diodes into one position in order to increase a luminance. Accordingly, since a light emitted from the laser diode is a diverging light, there is used a configuration such that a diverging light emitted from each laser diode is converted into an approximately parallel light by a lens corresponding to each laser diode, and then the plurality of lights being approximately parallel are condensed by a condenser lens.
Further, as described in JP2013-73079A, in order to condense a light without using a condenser lens, there is also proposed a method where a plurality of lights emitted from a plurality of laser diodes are condensed into the same position by a placement such that an optical axis of the laser diode shifts from an optical axis (center) of the corresponding lens in the direction to be perpendicular to the optical axis of the corresponding lens.
In order to realize a light source apparatus in which both a high power and a downsizing are achieved at the same time, it is necessary to make narrower a distance between laser diodes and a distance between lenses corresponding to the laser diodes as well as increase the number of the laser diodes. In this case, in JP2013-73079A, since the optical axis of the laser diode shifts from the optical axis (center) of the corresponding lens, if a diverging angle of the light emitted from the laser diode becomes large, the light may enter a neighboring lens and may be emitted to an unexpected direction. Further, it may cause a stray light.